Does anyone know how to rig a truck/trailer so that the trailer follows the truck in a realistic way?
I actually managed to make it work using Bones and kinematics.
Basically I used the description from:
How to IK rig legs

.. to create an inverse kinematic constrain.
But additionally I added a copy-constrain from the "target_bone" to the foot and then it worked. (target copies from foot)

I cascaded it 3 times to get an articulated trailer:


Edit: Here is the dependencies I have for one instance:

From How to IK rig legs :


'foot' is child of 'shin'
'shin' has IK constrain from 'control'
'foot' copies rotation from 'control'


At this point you should be able to move the foot and the shin changes accordingly

My Addition:


'control' copies location from 'foot'


Note: that these constrains must be bone constrains (i.e. in pose mode) not object constrains.